Coexistence of magnetic order and persistent spin dynamics in a quantum kagome antiferromagnet with no intersite mixing
| Autor: | J.-X. Mi, J. Â. A. Â. T. Verezhak, W. Sun, Matej Pregelj, Tian Shang, Martin Klanjšek, M. Gomilšek, Andrej Zorko, Zvonko Jagličić, James S. Lord |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Physics
Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Magnetic moment FOS: Physical sciences 02 engineering and technology Muon spin spectroscopy 021001 nanoscience & nanotechnology 01 natural sciences Magnetization Paramagnetism Condensed Matter - Strongly Correlated Electrons Lattice (order) 0103 physical sciences Antiferromagnetism Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Ground state Quantum |
| Zdroj: | Physical review B, 2019, Vol.99(21), pp.214441 [Peer Reviewed Journal] |
| Popis: | One of the key questions concerning frustrated lattices that has lately emerged is the role of disorder in inducing spin-liquid-like properties. In this context, the quantum kagome antiferromagnets YCu$_3$(OH)$_6$Cl$_3$, which has been recently reported as the first geometrically perfect realization of the kagome lattice with negligible magnetic/non-magnetic intersite mixing and a possible quantum-spin-liquid ground state, is of particular interest. However, contrary to previous conjectures, here we show clear evidence of bulk magnetic ordering in this compound below $T_N=15$\,K by combining bulk magnetization and heat capacity measurements, and local-probe muon spin relaxation measurements. The magnetic ordering in this material is rather unconventional in several respects. Firstly, a crossover regime where the ordered state coexists with the paramagnetic state extends down to $T_N/3$ and, secondly, the fluctuation crossover is shifted far below $T_N$. Moreover, a reduced magnetic-entropy release at $T_N$ and persistent spin dynamics that is observed at temperatures as low as $T/T_N=1/300$ could be a sign of emergent excitations of correlated spin-loops or, alternatively, a sign of fragmentation of each magnetic moment into an ordered and a fluctuating part. Published in PRB |
| Databáze: | OpenAIRE |
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